Webuild on a funded longitudinal birth cohort study, R01 R01ES027424-01A1,investigating the effects of prenatal BP exposure on mother-infant interaction, maternal estrogen signaling (esr1), and offspring neurodevelopment. Prior animal studies show adverse effects of BP exposure on estrogen signaling and mother-infant interaction; the R01 seeks to extend these findings to humans. This Administrative Supplement investigates the effects of BP exposure on peripartum depression (periPD) in these same women. The peripartum period, involving great hormonal and social change, poses high depression risk; 3rd trimester altered estrogen signaling predicts periPD postpartum. PeriPD affects mother-infant interaction and child health outcomes. Moreover, periPD may mediate associations between BP exposure and altered mother-infant interaction. Hormonal/social change affect brain function as well, but little is known about the neurobiology of periPD. Understanding altered neural functioning in relation to periPD may elucidate biomarkers for risk and novel targets for pharmacologic intervention. The funded R01 recruits minority/low-income pregnant women from obstetric clinics associated with Columbia Presbyterian Hospital. In this underserved population, multicultural factors impact access to/stigma of/mental health care. We propose to study periPD by adding a prenatal psychiatric interview, a self-report measure of periPD symptoms, and neuroimaging, to the funded R01. We will assess prevalence of depression/associated psychiatric problems in the last trimester; measure symptoms specific to periPD at 3-months postpartum; and estimate the attributable risk of BP and psychosocial stress on diagnosed prenatal depression and periPD at 3 months postpartum. Establishing links between BP exposure and periPD is important for low income women who are at greater risk for neurotoxicant exposure. We will use task-based fMRI in 25 high- and 25 low-depression mothers to examine associations between BP exposure, periPD symptoms, and functional activation of reward circuitry. We hypothesize that increased BP exposure will be associated with reduced reward processing and increased depression in the postpartum period. Our plan is consistent with goals of the Office of Research on Women's Health (ORWH) PA 18-676 targeting ?health disparities among women of populations in the US who are understudied, underrepresented and underreported in biomedical research.? This proposal fills a critical gap in understanding periPD in minority/low-income mothers who have reduced access to mental health care: to our knowledge, no study has examined effects of BP on periPD and the associated neural correlates, much less in low-income minority women.